We present a graphical user interface (GUI) for easy, intuitive control of a group of mobile robots moving in formation, and we give a short description of the general, local, distributed formation algorithm underlying the GUI. In spite of the high level of abstraction of the GUI, it captures the full functionality of the algorithm. The GUI has been tested with robots running in a simulator, and the formation algorithm itself has also been tested with real robots. We show results from experiments in both scenarios.